We can’t say we weren’t warned. For years, scientists have argued that human civilization must prevent the planet’s average annual temperature from rising by more than 2 degrees Celsius—or face certain catastrophe. Once we pass that critical threshold, according to the Intergovernmental Panel on Climate Change, life on planet earth is going to be a lot less fun. Think droughts, floods, superstorms, food shortages, and widespread extinctions.

Now, as forest fires rage and Delaware-sized chunks break off from Antarctica, scientists have more grim news: We’re going to hit the two-degree mark by the end of this century. Even if we manage to cut carbon emissions drastically, it’s simply too late—with one big caveat. If we can find some way to suck excess greenhouse gasses out of the atmosphere, we may still avert the very worst catastrophes.